cptt01.f3
Usage
Functions/Subroutines
CPTT01
Function/Subroutine Documentation
subroutine cptt01 (integer n, real, dimension( * ) d, complex, dimension( * ) e, real, dimension( * ) df, complex, dimension( * ) ef, complex, dimension( * ) work, real resid)
CPTT01
Purpose:
!> !> CPTT01 reconstructs a tridiagonal matrix A from its L*D*L' !> factorization and computes the residual !> norm(L*D*L' - A) / ( n * norm(A) * EPS ), !> where EPS is the machine epsilon. !>
Parameters
N
!> N is INTEGER !> The order of the matrix A. !>
D
!> D is REAL array, dimension (N) !> The n diagonal elements of the tridiagonal matrix A. !>
E
!> E is COMPLEX array, dimension (N-1) !> The (n-1) subdiagonal elements of the tridiagonal matrix A. !>
DF
!> DF is REAL array, dimension (N) !> The n diagonal elements of the factor L from the L*D*L' !> factorization of A. !>
EF
!> EF is COMPLEX array, dimension (N-1) !> The (n-1) subdiagonal elements of the factor L from the !> L*D*L' factorization of A. !>
WORK
!> WORK is COMPLEX array, dimension (2*N) !>
RESID
!> RESID is REAL !> norm(L*D*L' - A) / (n * norm(A) * EPS) !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 91 of file cptt01.f.